Gavin Henson could be in line for a first Six Nations appearance since 2009 after being included in Warren Gatland's 35-man training squad.

The 29-year-old Cardiff Blues back has not featured for his country since dislocating a bone in his wrist in the pre-World Cup friendly victory over England, and has played just three games for his region since joining in October.

Despite his lack of action, Henson is rated highly by the Wales coaching team and his ability to cover at fly-half, centre and full-back makes him a valuable commodity.

There are six uncapped players in the group, the most surprising selection being the 18-year-old Blues wing Harry Robinson. The others are the in-form Ospreys centre Ashley Beck and scrum-half Rhys Webb and the Scarlets trio of prop Rhodri Jones, lock Lou Reed and full-back Liam Williams.

Gatland has also included six who play out outside Wales – the France-based trio James Hook, Mike Phillips and Lee Byrne, the Exeter prop Craig Mitchell, the Saracens prop Rhys Gill and the Sale back-rower Andy Powell.

Those six will not attend all of Wales's pre-tournament training camp in Spala, Poland, but will be present for three days – the maximum stipulated by International Rugby Board regulations as they are not obliged to be released by their clubs for the full seven-day camp.

Gatland has been deprived of his first-choice second-row pairing through injury with Alun Wyn Jones and Luke Charteris missing out, while the Scarlets back-rowers Josh Turnbull and Rob McCusker are also ruled out along with the Newport Gwent Dragons hooker Lloyd Burns.

There was no place, meanwhile, for the Scarlets fly-half Stephen Jones. The 34-year-old has won a record 104 caps for his country but his latest non-selection following his omission from the squad to face Australia in December suggests his Test career may be at an end.

Gatland said: "We have had to strike a balance with this squad. The majority are those players who excelled for Wales during the Rugby World Cup, but we are also taking the opportunity to look at one or two youngsters before probably cutting our numbers even further before the start of the Six Nations.

"We have kept a couple of older heads and we have injuries, with Alun Wyn Jones, Josh Turnbull, Rob McCusker and Luke Charteris all unavailable to us, but the emphasis on development and planning for the future is there for everyone to see.

"These are exciting times for Welsh rugby. We showed a huge amount of potential at the Rugby World Cup in New Zealand and we'll be working as hard as humanly possible to ensure we reach our potential in this year's Six Nations Championship."